Micro device

ABSTRACT

Resonators  4  and  5  are able to oscillate horizontally and vertically to substrate  1 . Resonator  4  is primarily composed of a supporting portion in stationary contact with substrate  1 , a movable portion including a contact surface making contact with resonator  5  and a contact surface making contact with electrode  7 , and a crossing portion that couples the supporting portion and movable portion. Electrode  6  is disposed in the direction in which resonator  5  is spaced apart from resonator  4 . Electrode  7  is disposed in the direction in which resonator  4  is spaced apart from resonator  5 . Electrode  9  is disposed in a position that causes resonator  5  to generate electrostatic force in a direction different from the direction of both forces of attraction acting between resonators  4  and  5  and between resonator  5  and electrode  6.

TECHNICAL FIELD

[0001] The present invention relates to a micro device used in electriccircuitry.

BACKGROUND ART

[0002] One of well-known conventional techniques is described in“Introduction to Microelectromechanical Microwave Systems”, P122, ArtechHouse Publishers.

[0003] The details will be described with reference to FIGS. 1 and 2.FIG. 1 is a cross-sectional view of a switch having a membranestrtucture composed of membranes. When breaking a signal, as shown inFIG. 2, static electrocity is applied to bring a membrane into contactwith an electrode, while being not applied in passing a signal.

[0004] However, in the conventional device, since a switch isshort-circuited to attenuate signals, a reflected wave is generated onthe short-circuited surface, whereby exessive power is sent back to anamplifer diposed before the switch and destroys the amplifer. Further,there is another problem that since a membrane and electrode areelectrically coupled when not spaced adequately, a passage loss occurswhen the swich is ON. Furthermore, when a distance between the membraneand electrode is large, required electrostatic force becomes too large,and an applied volatge becomes too high, resulting in another problem.

DISCLOSURE OF INVENTION

[0005] It is an object of the present invention to provide a microdevice capable of securing higher isolation with a low voltage.

[0006] The object is achieved in a micro device by bringing into contactwith or separating independently a plurality of resonators for feedingor interrupting electric signals with static electricity, therebyobtaining a distance twice that corresponding to an applied voltage andsecuring higher isolation with a low voltage.

BRIEF DESCRIPTION OF DRAWINGS

[0007]FIG. 1 is a cross-sectional view of a switch having a membranestructure composed of membranes;

[0008]FIG. 2 is another cross-sectional view of the switch having themembrane structure composed of membranes;

[0009]FIG. 3 is a diagram illustrating a configuration of a micro deviceaccording to a first embodiment of the present invention;

[0010]FIG. 4 is a diagram illustrating operation of the micro deviceaccording to the above embodiment;

[0011]FIG. 5 is another diagram illustrating operation of the microdevice according to the above embodiment;

[0012]FIG. 6 is another diagram illustrating operation of the microdevice according to the above embodiment;

[0013]FIG. 7 is another diagram illustrating operation of the microdevice according to the above embodiment;

[0014]FIG. 8 is another diagram illustrating operation of the microdevice according to the above embodiment;

[0015]FIG. 9 is another diagram illustrating operation of the microdevice according to the above embodiment;

[0016]FIG. 10 is a diagram illustrating an example of frequencycharacteristics of the micro device according to the above embodiment;

[0017]FIG. 11 is a cross-sectional view in processes for manufacturingthe micro device according to the above embodiment;

[0018]FIG. 12 is another cross-sectional view in processes formanufacturing the micro device according to the above embodiment;

[0019]FIG. 13 is another cross-sectional view in processes formanufacturing the micro device according to the above embodiment;

[0020]FIG. 14 is another cross-sectional view in processes formanufacturing the micro device according to the above embodiment;

[0021]FIG. 15 is another cross-sectional view in processes formanufacturing the micro device according to the above embodiment;

[0022]FIG. 16 is another cross-sectional view in processes formanufacturing the micro device according to the above embodiment;

[0023]FIG. 17 is a diagram illustrating a schematic configuration of aswitch according to a second embodiment of the present invention;

[0024]FIG. 18 is a diagram illustrating an electrode pattern on asubstrate of the switch according to the above embodiment;

[0025]FIG. 19 is a diagram illustrating a cross section of the switchaccording to the above embodiment;

[0026]FIG. 20 is a diagram illustrating a schematic configuration of aswitch according to a third embodiment of the present invention;

[0027]FIG. 21 is a diagram illustrating an occurrence of a fixed endwith a cantilever in the switch according to the above embodiment; and

[0028]FIG. 22 is a diagram illustrating operation of the switchaccording to the above embodiment.

BEST MODE FOR CARRYING OUT THE INVENTION

[0029] A micro device of the present invention has a plurality offine-structure resonators that is brought into contact with one anotherby attraction due to static electricity, a plurality of first electrodesthat generates attraction with the resonators due to static electricityto separate the resonators, and a first applying section that applies avoltage to the plurality of first electrodes, where a signal is passedthrough the resonators when the resonators are in contact with oneanother, while the signal passed through the resonators is interruptedwhen the resonators are separated.

[0030] According to this configuration, since each of the resonators ismoved in the direction in which the resonators are spaced apart from oneanother, it is possible to obtain a distance twice that corresponding toan applied voltage, and to secure higher isolation with a low voltage.

[0031] In the micro device of the present invention, the resonators haveconductive surfaces to be in contact with one another, and conduct adirect signal when being in contact with one another.

[0032] According to this configuration, the micro device functions as aswitch for conducting direct signals.

[0033] In the micro device of the present invention, the resonators haveinsulating surfaces to be in contact with one another, and conduct analternating signal when being in contact with one another.

[0034] According to this configuration, the micro device functions as aswitch for conducting alternating signals.

[0035] In the micro device of the present invention, the firstelectrodes are connected to a ground or a power supply throughresistance with characteristic impedance corresponding to a frequency ofthe alternating signal passed through the resonators.

[0036] According to this configuration, it is possible to preventreflection of the signal in interrupting the signal.

[0037] The micro device of the present invention further has a secondelectrode that generates attraction with the resonators in directionsexcept a direction in which attraction between the resonators isgenerated and a direction in which attraction between the resonators andthe first electrodes is generated, and a second applying section thatapplies a direct signal between the second electrode and resonators.

[0038] According to this configuration, since it is possible to controlthe resonators to connect as a switch or to oscillate as a filerindependently, the micro device has switching operation with filteringfunction.

[0039] The micro device of the present invention further has a samenumber of second electrodes as the number of the resonators, where thesecond electrodes are disposed in positions such that the directionbetween the resonators and the first electrodes is perpendicular to thedirection between the resonators and the second electrodes, and thesecond applying section applies alternating signals with differentfrequencies for each of the second electrodes.

[0040] According to this configuration, it is possible to broaden afrequency band with which signals are passed through the filter.

[0041] The micro device of the present invention causes signals to bepassed between the second electrodes and the resonators.

[0042] According to this configuration, it is possible to separate asignal for each frequency component.

[0043] The micro device of the present invention further has a sealingsection that vacuum-seals the resonators.

[0044] According to this configuration, it is possible to switch betweenconduction and interruption of signal at high speed.

[0045] Embodiments of the present invention will be described below withreference to accompanying drawings.

[0046] (First Embodiment)

[0047]FIG. 3 is a diagram illustrating a configuration of a micro deviceaccording to the first embodiment of the present invention. The microdevice in FIG. 3 is primarily composed of substrate 1, input/outputports 2 and 3, resonators 4 and 5, electrodes 6 to 9, and direct currentsources 14 and 15, and each of “11” to “14” denotes a control signal. Onsubstrate 1 are integrated resonators 4 and 5 and electrodes 6 to 9.Substrate 1 is preferably an insulator or semiconductor.

[0048] Input/output ports 2 and 3 are terminals for inputting/outputtinga signal to/from a switch. Input/output port 2 is electrically connectedto resonator 5. Similarly, input/output port 3 is electrically connectedto resonator 4. The micro device enables signals to be passed frominput/output port 2 to input/output port 3 through resonators 5 and 4.Further, signals may be passed from input/output port 3 to input/outputport 2.

[0049] Resonators 4 and 5 are able to oscillate horizontally andvertically to substrate 1. Resonator 4 is primarily composed of asupporting portion in stationary contact with substrate 1, a movableportion including a contact surface making contact with resonator 5 anda contact surface making contact with electrode 7, and a crossingportion that couples the supporting portion and movable portion. Forexample, resonators 4 and 5 may be implemented by forming into acantilever-beam structure. Direct potential is applied to resonators 4and 5 through an inductor. Electrodes 6 to 9 are used to apply staticelectricity to the resonators.

[0050] Electrode 6 is preferably disposed in the direction in whichresonator 5 is spaced apart from resonator 4. In other words, it ispreferable that resonator 5 is present between resonator 4 and electrode6, attraction acting between resonators 4 and 5 is present in the sameaxis of the attraction between resonator 5 and electrode 6, and thatelectrode 6 is disposed in the inverse side. Similarly to electrode 6,electrode 7 is preferably disposed in the direction in which resonator 4is spaced apart from resonator 5.

[0051] Electrode 9 is disposed in a position that causes resonator 5 togenerate the electrostatic force in a direction different from thedirection of both forces of attraction acting between resonators 4 and 5and between resonator 5 and electrode 6. For example, such a position ispreferable that causes resonator 5 to generate the electrostatic forcein the direction perpendicular to the direction of both forces ofattraction acting between resonators 4 and 5 and between resonator 5 andelectrode 6.

[0052] In other words, it is preferable that a surface of resonator 5opposite to electrode 9 is in the direction perpendicular to contactsurfaces between resonators 4 and 5 and between resonator 5 andelectrode 6. Similarly, electrode 8 is disposed in a position thatcauses resonator 4 to generate the electrostatic force in a directiondifferent from the direction of both forces of attraction acting betweenresonators 4 and 5 and between resonator 4 and electrode 7.

[0053] Control signal 10 is a signal for use in applying a voltage toelectrode 6. Similarly, control signal 13 is a signal for use inapplying a voltage to electrode 7. Control signal 11 is a signal for usein applying an alternating voltage to electrode 9. Similarly, controlsignal 12 is a signal for use in applying an alternating voltage toelectrode 8.

[0054] DC electrode 14 applies a direct voltage to resonator 5.Similarly, DC electrode 15 applies a direct voltage to resonator 4.

[0055] A method of operating the switch will be described below. FIGS. 4to 7 are diagrams illustrating the operation of the switch of thisembodiment. FIG. 4 shows an upper view of the switch being OFF, FIG. 5shows a cross-sectional view of the switch being OFF, FIG. 6 shows anupper view of the switch being ON, and FIG. 7 shows a cross-sectionalview of the switch being ON. In making the switch OFF, for example,direct voltage Vc is applied to DC electrodes 14 and 15. When a voltageof −Vc is applied to electrodes 6 and 7, the electrostatic force isgenerated, resonator 4 is attracted towards electrode 7, resonator 5 isattracted towards electrode 6, and thus electrodes are electricallycoupled to respective resonators. At this point, electrodes 6 and 7 havesuch resistance that corresponds to characteristic impedance when theswitch is seen from the input/output terminals. When resonator 4 isbrought into contact with electrode 6, any reflected wave is notgenerated due to the resistance. Further, since two resonators, 4 and 5,are moved to separate from each other, it is possible to obtain adistance twice that corresponding to the applied voltage, and to securehigher isolation.

[0056] When making the switch ON next, for example, −Vc is applied to DCelectrode 14, +Vc is applied to DC electrode 15, +Vc is applied toelectrode 6, and −Vc is applied to electrode 7. Resonators 4 and 5 areattracted to each other and electrically coupled.

[0057] At this point, when being physically in contact with each other,resonators 4 and 5 are capacity-coupled with dielectric films on thecontact surface, while being resistance-coupled with no dielectric filmon the contact surface. In the case of capacity coupling, the devicefunctions as a switch with frequency characteristics. In the case ofresistance coupling, a DC signal is passed from DC electrode 14 to DCelectrode 15 and thus causes a short circuit, it is required to provideresistance as a substitute for an inductor or in series with theinductor.

[0058] Each of resonators 4 and 5 only requires in shape a size enablingtheir contact and separation by electrostatic force in a predeterminedtime. For example, resonators 4 and 5 are each in the shape of a cubewith a length of 500 μm, thickness of 2 μm and width of 2 μm, anddisposed such that a gap between resonators 4 and 5 is 0.6 μm, a gapbetween resonator 4 and electrode 7 is 0.6 μm, and a gap betweenresonator 5 and electrode 6 is 0.6 μm. When a thickness of theinsulating material is 10 nm, applying 7v enables the resonators torespond in 5 μs or less. Further, a passage loss of SW is made 0.5 dB orless.

[0059] The function as a filter will be described below. FIGS. 8 and 9are diagrams illustrating the operation of the micro device of thepresent invention. As illustrated in FIG. 8, when resonators 4 and 5 arein contact with each other to make the switch ON and an alternatingelectric field with a desired frequency and amplitude is applied toresonators 4 and 5 respectively from electrodes 8 and 9, resonator 4 and5 are driven and oscillate with a frequency corresponding to the controlsignal.

[0060] As a result, the capacity between resonator 4 and electrode 8varies. The impedance varies with frequency corresponding to the cycleof the capacity variation, whereby it is possible to select a signalwith the frequency. Resonator 5 and electrode 9 are the same as theforegoing in behavior.

[0061] At this point, when the alternating electric fields input toelectrodes 8 and 9 are in phase, as shown in FIG. 9, resonators 4 and 5oscillate in twisting direction.

[0062] When the alternating electric fields input to electrodes 8 and 9are in opposite phase, since forces acting between resonator 4 andelectrode 8 and between resonator 5 and electrode 9 are attraction orrepulsion, as shown in FIG. 8, resonators 4 and 5 tend to oscillate invertical mode. By designing shapes of resonators 4 and 5 and electrodes8 and 9, and distances between resonator 4 and electrode 8 and betweenresonator 5 and electrode 9 such that a resonance frequency of each modebecomes a desired value to control modes of vibration, it is possible tovary the resonance frequency of the filter readily.

[0063] In the above description, alternating signals are applied toelectrodes 8 and 9 to cause resonators 4 and 5 to oscillate, wherebywith respect to signals passed through resonators 4 and 5, generated aresignals with a frequency being passed through and signals with afrequency being not passed through and thus the device serves as afilter. However, as a method of causing resonators 4 and 5 to oscillate,other methods are applicable.

[0064] In other words, it is not always required to apply an alternatingelectric field from the outside, and resonators 4 and 5 may be driven bythe electrostatic force that high-frequency signals input to theresonators have.

[0065] Some configurations are considered as the filtering operation insuch cases. For example, controls signals 11 and 12 in FIG. 1 may bereplaced with loads to implement the filtering. Some figures showschematic configurations of the embodiment. (For example,) when acontrol signal is not input from the outside, resonators 4 and 5 aredriven by the electrostatic force that signals passed through resonators4 and 5 have.

[0066] When the signals passed through resonators 4 and 5 containsignals with a natural frequency obtained when resonators 4 and 5 arecoupled, resonators 4 and 5 oscillate greatly. At this point, forexample, when the oscillation mode is set at a vertical oscillationmode, resonators 4 and 5 greatly oscillate vertically to the substrate,and a gap between resonators 4 and 5 and electrodes 8 and 9 varies,resulting in electrical coupling.

[0067] That is, since resonators 4 and 5 oscillate with the naturalfrequency, signals with the natural frequency are selectively coupled toelectrodes 8 and 9, and are not conveyed to input/output ports, thushaving so-called notch filter effect. In this state, when electrodes 8and 9 are connected to terminals and the natural frequency of resonators4 and 5 is designed to a desired value, the device can be used as aduplexer.

[0068] Further, in inputting signals from the outside, control signal 11or control signal 12 is input to oscillate resonators 4 and 5. Thesignal with the natural frequency causes resonators 4 and 5 to oscillatestrongly, and is capable of selectively canceling only the signal withthe frequency used in oscillation.

[0069] Furthermore, the control signal is not always required to havethe natural frequency, and only required to have the electrostatic forcecapable of oscillating resonators 4 and 5.

[0070] For example, when electrodes 8 and 9 are not given controlsignals as their inputs and output terminals are connected, signalsinput from input terminals oscillate resonators 4 and 5, and onlysignals with frequencies around the natural frequency are selectivelyoutput from the output terminals.

[0071] When a single resonator is assumed, since the Q-value of theresonator is high, the resonance frequency is steep, and it is notpossible to selectively fetch signals except only the signal with thenatural frequency. However, in the micro device of the presentinvention, since two same resonators are coupled to oscillate, it ispossible to cause oscillations separately in two modes between which isthe natural frequency of a single resonator. In other words, two modesoccur where two resonators oscillate in the same direction or inopposite phase, and the device operates as a filter with a band of Δf.

[0072]FIG. 10 is a diagram illustrating an example of frequencycharacteristics of the micro device in this embodiment. In FIG. 10 thespectrum shown by dotted line indicates the natural frequency of asingle resonator. In FIG. 10 the spectrum shown by solid line indicatesone obtained by coupled two resonators. A desired band varies dependingon the applied system in order to apply the device to a filter, varyingthe degree of coupling of resonators varies the band.

[0073] Since coupled resonators 4 and 5 are considered to form adoubly-supported-beam structure, the natural frequency is indicated withequation (1): $\begin{matrix}{f = {1.03\frac{t}{L^{2}}\sqrt{\frac{E}{\rho}}}} & (1)\end{matrix}$

[0074] where, t is a thickness of the beam, L is a length of the beam, Eis the Young's modulus of a material composing the beam, and ρ indicatesa density. In order to obtain a desired frequency, controlling a shapeof a beam is capable of setting a desired frequency.

[0075] Thus, the micro device of this embodiment is capable of operatingas a device with two functions, i.e., as a switch by using oscillationin horizontal direction as in the first embodiment and as a filtereasily capable of canceling or selecting signals with a desiredfrequency by using oscillation in vertical direction.

[0076] Examples of processes of forming the above-mentioned switch willbe described below. FIGS. 11 to 16 are cross-sectional views inprocesses for manufacturing the micro device according to thisembodiment. As illustrated in FIG. 11, by subjecting high-resistancesilicon substrate 21 to thermal oxidation, silicon oxide film 22 with athickness of about 300 nm is formed on high-resistance silicon substrate21. Then, silicon nitride film 23 is deposited with a thickness of 20 nmusing a pressure reducing CDV method. Further, silicon oxide film 24with a thickness of 50 nm is deposited using the pressure reducing CDVmethod.

[0077] Subsequently, as shown in FIG. 12, a sacrifice layer with athickness of 2 μm composed of a photoresist coating is spin-coated,exposed and developed on silicon oxide film 24, and baked at 140° C. forten minutes with a hotplate to form sacrifice layer 25.

[0078] Then, as shown in FIG. 13, Al 26 is deposited with a thickness of2 μm on the entire surface of the substrate, and patterns 27 are formedby photoresist coating such that the resist is left in a predeterminedarea.

[0079] Next, as shown in FIG. 14, the dry etching with Al is performedusing the patterns composed of the photoresist coating as masks, therebyforming beams 28, and then patterns 27 and sacrifice layer 25 composedof photoresist coating are removed with O₂ plasma. The aforementionedprocesses form beams 28 with gap 29 with the surface of the substrate.

[0080] Further, as shown in FIG. 15, silicon nitride film 30 with athickness of 50 nm is deposited over the entire surface by plasma CDV,whereby the silicon nitride film is formed on silicon oxide film 24 andaround beams 28 on the surface of the substrate.

[0081] Finally, as shown in FIG. 16, etchback is performed on thesilicon nitride film under condition providing a selective ratio to thesilicon oxide film, for example, with a thickness of 100 nm or more thatis more than the deposit film thickness using the dry etching methodwith anisotropy, whereby the etching is performed so that the beam hasno silicon nitride film on its upper surface with the silicon nitridefilm left on its side surface 31.

[0082] In addition, while in this embodiment a high-resistance siliconsubstrate is used, either an insulator or semiconductor is applicable.For example, general silicon substrates, chemical semiconductors andinsulating substrates are applicable.

[0083] Further, while silicon oxide film 22, silicon nitride film 23 andsilicon oxide film 24 are formed on high-resistance silicon substrate 21as insulating films, formation of the insulating films may be omittedwhen the resistance of the substrate is adequately high. Furthermore, athree-layer insulating film, i.e., silicon oxide film 22, siliconnitride film 23 and silicon oxide film 24, is formed on the siliconsubstrate. However, when the thickness of silicon nitride film 23 isthicker enough than that of the silicon nitride film deposited on thebeam, i.e., when the thickness is not removed even after so-calledetchback process, the process of forming silicon oxide film 24 can beomitted.

[0084] In addition, while this embodiment uses Al as a material forforming the beam, it may be possible to use other metal materials suchas Mo, Ti, Au and Cu, semiconductor materials with high-concentrationimpurities contained therein such as, for example, amorphous silicon andconductive polymer materials. Further, while sputtering is used as afilm formation method, other methods such as CVD and plating may beused.

[0085] (Second Embodiment)

[0086] The second embodiment of the present invention will be describedwith reference to FIGS. 17 to 19. FIG. 17 is a diagram illustrating aschematic configuration of a micro device of the second embodiment ofthe present invention. A signal input from input/output terminal 33 iselectrically coupled to flatbed resonator 36 through signal line 35,flatbed resonator 36 is further electrically coupled to signal line 34,and thereby the signal is output from input/output terminal 32. Thuscoupled signal is selectively coupled to a signal with the frequencywith which flatbed resonator 36 oscillates, and thereby the deviceserves as a filter.

[0087] The specific contents will be described below. A plurality ofelectrodes 50 is provided on a substrate side of flatbed resonator 36, aplurality of electrodes 30 is provided on the substrate, and it ispossible to apply a voltage independently to each electrode with acontrol signal generated from control signal generating mechanism 49,thereby enabling arbitrary electrostatic force to be generated betweenflatbed resonator 36 and substrate 30. Therefore, it is possible toapply the electrostatic force to flatbed resonator 36 in the arbitrarydirection by arbitrary force. By varying the frequency, amplitude andposition of thus applied control signal, it is possible to control theoscillation frequency and oscillation mode of the flatbed resonator.

[0088] For example, electrode 38 is assumed to be comprised offan-shaped electrodes 51 to 54. When direct voltage −Vc is uniformlyapplied to all the flatbed resonator electrodes 50 and the controlsignal indicated by −Vc×Sin(fbt) is applied to all the electrodes (51 to54) on the substrate, the flatbed resonator is forced to oscillate witha frequency corresponding to frequency fb of the control signal.Further, when a control signal is applied to part of the electrodes inimpulse, the flatbed resonator is driven and oscillates with the naturalfrequency. The natural frequency is indicated with equation (2), where mand k respectively indicate mass and spring constant: $\begin{matrix}{{fc} = {\frac{1}{2\pi}\sqrt{\frac{k_{1}}{m}}}} & (2)\end{matrix}$

[0089] With direct voltage −V1 uniformly applied to electrodes 50 of theflatbed resonator and with direct voltage +V2 applied to electrodes 51and 53 on the substrate, a control signal indicated by −V1×Sin(fct) isapplied to electrodes 52 and 54 on the substrate to oscillate theflatbed resonator. At this point, as shown in FIG. 19, flatbed resonator36 bends due to the electrostatic force applied from electrodes 51 and53, and thereby the spring constant of the flatbed resonator varies.Therefore, according to equation (1), it is possible to vary the naturalfrequency of the flatbed resonator. Since it is thus possible toarbitrarily control the frequency and mode with which the flatbedresonator oscillates, it is possible to vary the center frequency ofpassage band of the filter.

[0090] (Third Embodiment)

[0091] The third embodiment of the present invention will be describedwith reference to FIGS. 20 to 22. FIG. 20 illustrates a schematicconfiguration of the third embodiment of the present invention, which issimilar to the second embodiment except cantilever 61 provided onflatbed resonator 66. Cantilever 61 has three-axis control mechanism(not shown) movable in the horizontal direction and vertical directionto come into contact with flatbed resonator 66 in arbitrary position. Inthe second embodiment, in order to control the mode and resonancefrequency with which the flatbed resonator oscillates, the electrostaticforce is applied from the outside to control the mode and frequency todesired ones. In this embodiment, cantilever 66 is physically broughtinto contact with the resonator and thereby a fixed end is provided inthe resonator arbitrarily, thereby controlling the oscillation mode andresonance frequency of the flatbed resonator. FIGS. 21 and 22 illustratean example. As shown in FIG. 21, when the cantilever is not in contact,flatbed resonator 71 oscillates with the basic mode (with the resonancefrequency of f0). On the contrary, as shown in FIG. 22, when theresonator is forcibly fixed by cantilever 61, the flatbed resonator isdivided into some resonators and oscillates with a plurality offrequencies (resonance frequencies f0, f1 and f2).

[0092] Further, an input signal input from signal line 65 may bedirectly input to resonator 66 as shown in FIG. 22. In this case, sincethe oscillation frequency varies with the position in which the signalline is fetched, it is possible to fetch signals with a plurality offrequencies.

[0093] As can be apparent from the foregoing, according to the microdevice of the present invention, by bringing into contact with orseparating independently a plurality of resonators for feeding orinterrupting electric signals with static electricity, it is possible toobtain a distance twice that corresponding to the applied voltage and tosecure higher isolation with a low voltage.

[0094] Further, according to the micro device of the present invention,since it is possible to arbitrarily vary the oscillation mode andfrequency with which the resonator oscillates, it is possible toarbitrarily set the power and frequency of a signal passed through thedevice.

[0095] This application is based on the Japanese Patent ApplicationsNo.2002-006908 filed on Jan. 16, 2002, and NO.2002-364322 filed on Dec.16, 2002, and entire contents of which are expressly incorporated byreference herein.

INDUSTRIAL APPLICABILITY

[0096] The present invention is suitable for use in micro devices usedin electric circuitry

1. A micro device comprising: a plurality of fine-structure resonatorsthat is brought into contact with one another by attraction due tostatic electricity; a plurality of first electrodes that generatesattraction with the resonators due to static electricity to separate theresonators; and a first applying section that applies a voltage to theplurality of first electrodes, wherein a signal is passed through theresonators when the resonators are in contact with one another, whilethe signal passed through the resonators is interrupted when theresonators are separated.
 2. The micro device according to claim 1,wherein the resonators have conductive surfaces to be in contact withone another, and conduct a direct signal when being in contact with oneanother.
 3. The micro device according to claim 1, wherein theresonators have insulating surfaces to be in contact with one another,and conduct an alternating signal when being in contact with oneanother.
 4. The micro device according to claim 1, wherein when each ofthe resonators and respective one of the first electrodes are broughtinto contact, the device has impedance, corresponding to a frequency ofan input signal, between an input terminal of the each of the resonatorsand an input terminal of the respective one of the first electrodes. 5.The micro device according to claim 1, further comprising: a secondelectrode that generates attraction with respective one of theresonators in directions except a direction in which attraction betweenthe resonators is generated and a direction in which attraction betweeneach of the resonators and respective one of the first electrodes isgenerated, wherein the device varies capacity with driving frequencybetween the second electrode and the respective one of the resonators,and the device has frequency selectivity.
 6. The micro device accordingto claim 5, further comprising: a load that is connected to the secondelectrode, wherein the device provides signals between the secondelectrode and the respective one of the resonators.
 7. The micro deviceaccording to claim 5, further comprising: a second applying section thatapplies a DC signal between the second electrode and the respective oneof the resonators, wherein the second applying section varies capacitybetween the second electrode and the respective one of the resonators.8. The micro device according to claim 1, further comprising: a samenumber of second electrodes as the number of the resonators, each of thesecond electrodes generating attraction with respective one of theresonators in directions except a direction in which attraction betweenthe resonators is generated and a direction in which attraction betweeneach of the resonators and respective one of the first electrodes isgenerated; and a second applying section that applies a DC signalbetween each of the second electrodes and the respective one of theresonators, wherein the second electrodes are disposed in positions suchthat the direction between the resonators and the first electrodes isperpendicular to the direction between the resonators and the secondelectrodes, and the second applying section applies alternating signalswith different frequencies for each of the second electrodes.
 9. Themicro device according to claim 1, further comprising: a sealing sectionthat vacuum-seals the resonators.